Landing: 4e0964279b73

Project / Subsystem

gcc / gcc/vect

Date

2026-05-20

Author

Alfie Richards

Commit

4e0964279b73d3af5b085f731c87c200b7564db4

Source

github

Perf win

Yes

Breaking

No

All attributes

project
gcc
subsystem
gcc/vect
patch_id
commit_hash
4e0964279b73d3af5b085f731c87c200b7564db4
source_type
github
headline
Vectorizer uses LOOP_VINFO_IV_INCREMENT for loop induction variables
tldr
Vectorizer now uses a new value, LOOP_VINFO_IV_INCREMENT, improving loop variant induction variable handling.
author
Alfie Richards
outcome
committed
performance_win
true
breaking_change
false
series_id
series_parts
[]
tags
  • vectorization
  • optimization
  • compiler
discussion_id_link
bugzilla_pr
date
2026-05-20T00:00:00.000Z

The GCC vectorizer introduces LOOP_VINFO_IV_INCREMENT to store the number of scalar iterations a vectorized loop iteration represents. This change allows induction variable (IV) updates and reductions to correctly use this value, including loop-variant IV increments. This simplifies internal logic by removing special cases for SELECT_VL and enables more flexible handling of pointer arithmetic in grouped loads and stores.